quality float switch?

[aquaman3680]

On drsfostersmith.com there is a thing called auto top off it works great

[davejnz]

I used kents float valve before,it has a tiny orifice where the water flows through and tends to clog up when useing kalk IME.I prefer this kind over KEnts.The name that is on it is floatvalve.com.They make them in different sizes,mine uses 1/4" RO tubeing
that connects to it.Since you plan on connecting you RO to it,make sure you get this style.Hindsight,since i do the gravity fed top-off with kalk/limewater,I would of went with the 3/8" tubeing float instead.
BTW,they are rated at 100PSI